Abstract Title
The Mechanical Wear Behavior of Meniscal Tissue is Highly Depth-Dependent
Abstract
Mechanical wear of soft connective tissue is a primary factor in degenerative joint disease, but little is known about the influence of tissue depth on meniscal wear rates. The superficial meniscal layer is composed of randomly organized fibers to resist shear stresses, while the inner layer has circumferentially organized fibers to resist hoop stresses. The objective of this study was to therefore determine how mechanical wear is influenced by the depth of the meniscus layers. A custom-built pin-on-plate device was used for creep testing, and to simulate wear by translating a 4-mm bovine cartilage pin relative to a 2-mm thick meniscus plate at a rate of 2Hz. Linear wear was recorded as the displacement of the meniscal tissue over a 10,000-cycle duration and visualized using 3D optical scanning techniques. Additionally, microscopy images were used to compare pre- and post-testing fiber alignment. Our results show that the inner layer increased linear wear by nearly 60% relative to the superficial layer (p = 0.001). The wear rate after the initial 2000 cycle (run-in) was approximately 74% greater for the inner layer. No significant difference was detected for fiber alignment between layers (p > 0.05). These results demonstrate the depth-dependence of meniscal mechanical wear and will help advance a mechanistic understanding of meniscus tissue.
The Mechanical Wear Behavior of Meniscal Tissue is Highly Depth-Dependent
Mechanical wear of soft connective tissue is a primary factor in degenerative joint disease, but little is known about the influence of tissue depth on meniscal wear rates. The superficial meniscal layer is composed of randomly organized fibers to resist shear stresses, while the inner layer has circumferentially organized fibers to resist hoop stresses. The objective of this study was to therefore determine how mechanical wear is influenced by the depth of the meniscus layers. A custom-built pin-on-plate device was used for creep testing, and to simulate wear by translating a 4-mm bovine cartilage pin relative to a 2-mm thick meniscus plate at a rate of 2Hz. Linear wear was recorded as the displacement of the meniscal tissue over a 10,000-cycle duration and visualized using 3D optical scanning techniques. Additionally, microscopy images were used to compare pre- and post-testing fiber alignment. Our results show that the inner layer increased linear wear by nearly 60% relative to the superficial layer (p = 0.001). The wear rate after the initial 2000 cycle (run-in) was approximately 74% greater for the inner layer. No significant difference was detected for fiber alignment between layers (p > 0.05). These results demonstrate the depth-dependence of meniscal mechanical wear and will help advance a mechanistic understanding of meniscus tissue.